[rygel] Added missing file

[Murray Cumming <murrayc src gnome org>]

commit e06b48d29a4c5f88ae7bd08d0d80c0d8536e5e74
Author: Murray Cumming <murrayc murrayc com>
Date:   Tue Nov 27 09:04:27 2012 +0100

    Added missing file

 .../gtkdoc/implementing-renderers.xml              |   38 ++++++++++++++++++++
 1 files changed, 38 insertions(+), 0 deletions(-)
---
diff --git a/doc/reference/librygel-renderer/gtkdoc/implementing-renderers.xml b/doc/reference/librygel-renderer/gtkdoc/implementing-renderers.xml
new file mode 100644
index 0000000..33fa1c3
--- /dev/null
+++ b/doc/reference/librygel-renderer/gtkdoc/implementing-renderers.xml
@@ -0,0 +1,38 @@
+<?xml version="1.0"?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
+               "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd"; [
+<!ENTITY % local.common.attrib "xmlns:xi  CDATA  #FIXED 'http://www.w3.org/2003/XInclude'">
+<!ENTITY url_refdocs_librygel_renderer_gst "http:/developer.gnome.org/librygel-renderer-gst/unstable/">
+]>
+
+<section id="implementing-renderers-gst">
+
+
+<para>
+This library may be used to create in-process UPnP/DLNA Renderers, or Players, via
+the <link linkend="RygelMediaRenderer">RygelMediaRenderer</link> class. For instance,
+this may be used to add UPnP/DLNA Renderer or Player capability to an existing media player application.
+See the derived
+<ulink url="&url_refdocs_librygel_renderer_gst;RygelPlaybinRenderer.html">RygelPlaybinRenderer</ulink>
+class, from librygel-renderer-gst, to see how this can be done with GStreamer.
+</para>
+
+<!-- TODO: Find a way to mention this C example code in the RygelPlaybinRenderer valadoc comments instead. -->
+<!--
+<para>
+This example program shows how to instantiate the renderer then configure its GStreamer playbin element
+and connect it to a network interface.
+</para>
+-->
+
+
+<!-- Do not indent the xi:include node. That puts spaces at the start of the code. -->
+<!-- TODO: Add a non-GST standalone-renderer example. Maybe use the same code as the example renderer plugin.
+<programlisting role="C">
+<xi:include  href="../../../../examples/standalone-renderer.c"
+    parse="text"
+    xmlns:xi="http://www.w3.org/2001/XInclude"/>
+</programlisting>
+-->
+
+</section>